1. Field of the Invention
The present invention relates to a disk drive unit.
2. Description of the Related Art
A disk drive unit, such as a HDD (Hard Disk Drive), for example, is one type of a rotating device. The disk drive unit may use a fluid dynamic bearing that rotatably supports a disk by providing a lubricant between a rotating body and a fixed body. In the disk drive unit mounted with the fluid dynamic bearing, it may be important, from the standpoint of enabling the use of the disk drive unit for a long time without an operation error, to manage an existing state of the lubricant, such as the amount of lubricant and an interface position of the lubricant, and to prevent scattering and leaking of the lubricant.
In order to accurately and easily confirm the interface position of the lubricant, a fluid dynamic bearing mechanism having a seal member formed by a translucent material has been proposed in Japanese Laid-Open Patent Publication No. 2012-089200, for example. Further, in order to prevent leaking of the lubricant, a fluid dynamic bearing unit having a bearing member formed with a ring-shaped groove to hold the lubricant that is provided to a predetermined lubricant level has been proposed in Japanese Laid-Open Patent Publication No. 2012-087867, for example.
In addition, in order to prevent the scattering and leaking of the lubricant, a disk drive unit having a cap member that covers a gas-liquid interface of a capillary seal part has been proposed in Japanese Laid-Open Patent Publications No. 2012-089200, No. 2012-087867, No. 2012-163203, and No. 2012-165627, for example.
However, in the disk drive unit having the fluid dynamic bearing, the lubricant may vaporize from the gas-liquid interface and adhere on the disk surface through a gap or the like, and an operation error may occur during a read or a write with respect to the disk. Such disk contamination caused by the vaporized lubricant adhering onto the disk surface may also occur in the configurations proposed in the Japanese Laid-Open Patent Publications No. 2012-089200, No. 2012-087867, No. 2012-163203, and No. 2012-165627 described above, for example, and cause the operation error of the disk drive unit. Particularly as the storage capacity of the disk drive unit becomes larger, it becomes more and more desirable to suppress adhesion of the lubricant onto the disk surface.